Focusing arrangement for cameras



April 1939- R E. CROWTHER 2,153,132

FOCUSING ARRANGEMENT FOR CAMERAS Filed Feb. 20, 1937 ZSheet's-Sheet 1 FIG].

Raymond Crowlher INVENTOR. BY W ATTORNEYS April R. E. CROWTHER 2,153,132

FOCUSING ARRANGEMENT FOR CAMERAS Fi-led Feb. 20, 1937 2 Sheets-Sheet 2 Raymond E.Crowther INVENT OR.

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ATTORNEYS Patented Apr. 4, 1939 UNITED STATES 2,153,132 FOCUSING ARRANGEMENT FOR CAMERAS Raymond E. Crowther, London, England, asslgnor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application February 20, 1937, Serial No. 126,935 In Great Britain May 22, 1936 4 Claims.

(i. e. a combination range finder and view finder).

. It is a particular object of the invention to pro-' vlde means whereby the focusing scale mounted 15 on the camera objective may be viewed through the eye-piece of the range finder whereby the.

focus may be adjusted until the scale reading thus viewed corresponds to the coincidence reading on the range finder scale which is viewed simul- 20 taneously.

' Various embodiments of the invention are shown in the accompanying drawings in which:

Figure 1 is a side elevation of one form of the invention wherein a mirror is mounted to one side 25 of the camera objective whereby the focusing scale may be viewed through the range finder eye-piece.

Figure 2 is a plan view of the arrangement shown in Figure 1.

30 Figure 3 is a'front view of a camera which is provided with another form of the invention in which the focusing scale extends to one side of the [camera objective, and may be viewed directly through the range finder eye-piece.

35 vFigure 4 shows the field of view which appears in the eye-piece of the range finder shown in Figure 3.

Figure 5 is an elevation partially cut away of another form of the invention wherein the camera 4 focusing means controls the position of an auxiliary scale which is mounted on the camera housing and which may be viewed through the range finder eye-piece simultaneously with the range finder scale.

Figure 6 shows the field of view as seen through the eye-piece of the range finder which is arranged as in, Figure 5.

Figure 7 similarly shows the field of view corresponding to Figures 1 and 2.

50 One form of the invention is shown in Figure 1 applied to a self erecting front camera having a housing Ill-and a cover II which is also the camera bed. An objective mount I2 is mounted in the usual way by means of supports l3 on the 55 camera bed II. In the well-known manner the erecting member It brings the objective 12 into operative position when the camera is opened. The objective mount 12 is provided with a suitable scale l5 and index [5' for indicating the distance for which the camera is focused. 5 A range finder I6 is mounted on the side of the camera housing l0 and is of the usual type including a fixed semi-transparent mirror H, a. rotatable mirror l8 whose angular position is de termined by a cam shaped lever l9, two windows 10 23 and 24 and an eye-piece 25. The position of the cam shaped lever' I9 is determined by the position of a small lug 20 against which the lever, I9 is urged as by a. spring l9 and which projects through a slot in the range finder housing l6. A small button 2| rigidly attached to the lug v2|] is positioned on the exterior of the range finder housing. The range finder is adjusted by push: ing the button 2| laterally sothat the lug slides along the slot in the camera housing and 20 moves the cam shaped lever Hi to rotate the mirror Hi to bring the two parts of the range; finder field into coincidence in the usual, wellknown manner. Thelug 20 carries a scale 227 which moves over a fixed index 22' (shown in 25 Figure '7) and which may be viewed simultaneously with the part of the field seen through the window 23, in the eye-piece 25 of the range finder. As shown in the drawings the eye of the observer is placed at the point 26 and receives light from 30 the subject (not shown) to be photographed, through both of the windows 23 and 24 of. the range finder. A mirror 21 is arranged to bring the -focusing scale I5 and index I5 into the field of view of the range finder.

As shown moreclearly in Figure 2 the mirror 21 is positioned to allow the focusing scale to be easily viewed in the "range finder eye-piece and to allow the camera to be closed conveniently.

Similar reference numerals refer to similar details in all of the drawings. How these various par-ts appear when viewed by the ob's'ervers eye 26 is clearly shown in Figure 7.

A somewhat different arrangement of the invention, shown in Figure 3, eliminates the mirror 21 by providing a disk shaped focusing scale 30 extending to one side of the lens mount instead of or in addition to the focusing scale l5 not shown in this figure. The rulings on this scale 30 face toward the rear of the camera or preferably the scale 30 itself is made of transparent material. The index 30' for the scale is mounted between the scale 30 and the eyepiece 23 of the range finder preferably near the scale 30. For convenience in closing the camera,

the scale 30 is made in two parts hinged on the line 31 so that an auxiliary section 38 which projects from the side of the camera objective may be folded over to lie on top of the other half of the scale 30 and thus does not interfere with closing the camera when the lens is focused in its infinity position.

When looking through the eye-piece of the range finder l6, one sees a field of view similar to that shown in Figure 4 wherein the subject being photographed appears as shaded portions 35 and 38 which will come into coincidence when the range finder. is adjusted in the well-known way.

The images of the'range finder scale 22 and its index 22', as reflected by the mirrors I8 and I1,

appear as shown in a suitable position of the upper half 3! of the range finder field. Across a corner of the lower half 34 of the range finder field one sees the scale and its index 30'. It will be understood that the two scales 22 and 30 may be caused to appear in any desired portions of the field of view.

In using a camera provided with the invention, the eye is placed near the eye-piece 25 and the range finder is adjusted by means of the button 2| until the two portions and 3B of the camera subjects as viewed are brought into coincidence. The reading on the range finder scale 22 as indicated by the index 22' is then noted, The camera objective is then focused manually until the reading on the scale 30 as indicated by the index 30' is the same as that appearing on the range finder scale 22. When thus azfiusted the camera is properly focused on the subject.

As is well-known, some cameras are made to focus by sliding forward a section of the camera bed carrying or comprising the objective mount. Many satisfactory arrangements for doing this are well-known in the art. In one such arrangement shown in Figure 5 the linear adjustment of the objective mount as a whole (rather than a rotational adjustment of the type described previously), is transmitted by the erecting member I to a sliding member 5| mounted in the camera housing and limited in its motion by pins and slots 52. This sliding member 5| carries a rack 53 which is in mesh with a pinion 54 which turns on an axle 55 and extends through the camera body- Ill into the range finder housing l6. An other rack 58 which is also in mesh wth the pinion 54 carries a scale 51 which is mounted near the range finder scale 22 and which is visible in the range finder eye-piece 25 not shown in this figure, by reflection from the mirrors i8 and. I! (the latter is not shown in this figure). The scale 22 may be adjusted in any suitable manual manner for example as in Figure 1, i. e., a stud 2| shown in cross section may extend through a slot in the range finder housing I6 and support an adjusting button similar to that shown as 2| in Figure 1. With this arrangement the camera focus 'as indicated by the scale 51 and the range finder adjustment as indicated by the scale 22 are both visible in the same half 33 of the range finder field of view shown in Figure 6. The images of the range finder scale 22 and the focusing scale,

51 have indexes 22' and 51' respectively.

The actual focusing adjustment may be accomplished by any suitable well-known means mounted on the camera bed H, or the axle 55 may extend through the range finder housing It to a knob (not shown) which may be rotated manually, thereby moving the sliding member 5| and the erecting member H.

It is to be understood that the invention is not limited to the specific structures shown but is of the scope of the appendedclaims.

What I claim and wish to protect by Letters Patent of the United States is:

1. A photographic camera having focusing means, a focusing scale for indicating the adjustment of the focusing means, a parallax type range finder mounted on the camera, a light deviating means therefor manually adjustable separately from the focusing means, a distance scale for indicating the range corresponding to the adjustment of the light deviating means, said distance scale being visible in the field of view of the range finder when sighted on a subject and optical means having substantially no effect on the range finder field of view secured to the camera for bringing into this field of view an image of said focusing scale.

2. A photographic camera having a lens, a lens mount, rotary means on the mount for focusing the lens, a focusing scale on the mount for indicating the adjustment of the focusing. means, a parallax type range finder mounted on the camera and adjustable separately from the focusing means, a distance scale visible through the eyepiece of the range finder for indicating the adjustment thereof, and a reflector on the lens mount for forming a reflection image of the focusing scale within the field of view of said range finder.

3. A photographic camera having a lens, means for focusing the lens, a focusing. scale for indicating the adjustment of the focusing means, a parallax type range finder mounted on the camera separate from the focusing means, a light deviating means in the range finder, means for adjusting the light deviating means separately from the focusing means, a distance scale visible in the eyepiece of the range finder for indicating the adjustment of the light deviating means, said focusing scale being positioned in the field of view of an observer taking a reading on said range finder so that the focusing scale and the distance scale may be compared.

4. In combination a camera having a lens and a focusing mechanism, a range finder secured to the camera, and having a movable element to adjust its setting, a scale in thefield of view of the range finder carried by said movable ele ment to indicate said setting, a second scale carried by said mechanism and extending laterally from the camera lens into the field of view of said range finder, whereby both scales may be viewed simultaneously with the range finder field.

RAYMOND E. CROWTHER. 

